From the manual - page 104...
GPS WAIT
and ALM:OO appear in the display when
the GPS receiver requires a download of the most current
almanacs from the satellite. This happens when
battery power has been reapplied following a battery
disconnect.
page 105
GPS
OK: GPS reception is available.
1 indicates a one-dimensional positioning
2 indicates a two-dimensional positioning
3 indicates a three-dimensional positioning
• S: indicates the number of satellites received
• ALM:
indicates the number of downloaded almanacs.